It’s been a long winter for fans of “The Good Wife”: a seemingly endless holiday hiatus, two episodes in January and then another break.

The CBS series returns on Sunday (9 p.m.) with a particularly funny storyline for beloved recurring character Colin Sweeney, making his eighth appearance on the show. Actor Dylan Baker actually does triple duty as the suave sociopath, his barely fictionalized TV double and the actor playing Sweeney.

Post: Colin Sweeney is delectably nasty, and he really seems to get under Alicia’s (Julianna Margulies) skin.Baker: He does make her question herself: “What is it about me that’s able to be charmed by a killer?” The writers have never told the cast whether Sweeney is guilty or not. Although the second murder [from Season 2], with the woman who was handcuffed to his ankle — yeah, he did her!

Your relish playing him is contagious.
The writers keep coming with things I can really get into. And they’re open. There was an episode [Season 4’s “The Wheels of Justice”] when I was deciding to marry [a woman played by] Morena Baccarin to have my child. As I was leaving the courtroom Alicia was saying to me, “You know that if you don’t have a prenup, she’s going to take everything.” They let me change my original response to “Well, I could just kill her” [laughs].

Sweeney’s relationship with his latest wife, played by Laura Benanti, is the best yet — she’s just as perverse as he is.
Laura embraced this whole idea … and we were simpatico immediately. We’ve known each other since we did “The Winter’s Tale” at the Williamstown Theatre Festival [in 2001]. She was Perdita and I was Camillo — every now and then I play a good guy.

How did you land the role of former Prime Minister John Major in “The Audience”?
Stephen Daldry, the director, asked me to audition. My accent was totally wrong for it. My go-to is a standard or upper-class British accent while Major has more of a London-suburb accent that he’s trying to make posh, without succeeding entirely. And just the chance to work with Helen Mirren … she’s pretty amazing.

And maybe a little daunting?
She’s incredibly giving, but I do have to say I have one scene where I say something and she comes back at me. One night she gave me a look that froze me to my core. I felt chills up and down my spine. So I experienced the full power of Helen Mirren onstage. And it was very exciting.